Treatment-related Lymphopenia in Patients With Stage III Non-Small-Cell Lung Cancer

Abstract

Background This study sought to estimate the severity, etiology, and clinical importance of treatment-related lymphopenia in patients with stage III non-small-cell lung cancer. Methods Serial lymphocyte counts and survival were analyzed retrospectively in 47 patients accounting for known prognostic factors. Results Total lymphocyte counts (TLCs) were normal before therapy and did not change following neoadjuvant chemotherapy. Following radiation, TLC fell by 67% (median 500 cells/mm3, p <.00001). Multivariate analysis revealed an association between severe TLC and survival (HR 1.70, 95% CI: 0.8–3.6). Conclusions Rapid and severe lymphopenia occurred in 50% of patients following radiation which was associated with reduced survival.

Stem Cell Transfusion Restores Immune Function in Radiation-Induced Lymphopenic C57BL/6 Mice

“…If the effect of radiation was only on circulating lymphocytes, and assuming that all circulating T cells were destroyed by irradiation, lymphopenia should not be observed for more than 90 days. Prolonged RIL is however observed in patients for more than 6 to 12 months after irradiation (2). This led us to speculate that apart from circulating lymphocytes, radiation could also affect stem cells in the BM that primarily replenishes the lymphocytes.…”

“…RIL is associated with treatment of many tumors (lung, colon, pancreas, breast, sarcomas, and glioblastoma) and associated with poor clinical outcomes (2,3,5,6). The biologic mechanisms leading to RIL are not clearly understood.…”

“…The biologic mechanisms leading to RIL are not clearly understood. T-cell renewal occurs approximately every 60 to 90 days (2,5). If the effect of radiation was only on circulating lymphocytes, and assuming that all circulating T cells were destroyed by irradiation, lymphopenia should not be observed for more than 90 days.…”

“…2). RIL is frequently observed in cancer patients undergoing radiotherapy to various sites, including brain, thorax, abdomen, and pelvis (2)(3)(4)(5). Recent clinical data indicate that RIL was associated with poor clinical outcome in patients with carcinomas of the lung, colon, pancreas, breast, sarcomas, and glioblastoma (2)(3)(4)6).…”

“…Radiotherapy was shown to decrease patients total lymphocyte counts to fall below 1,000/mL, a condition known as radiation-induced lymphopenia (RIL; ref. 2). RIL is frequently observed in cancer patients undergoing radiotherapy to various sites, including brain, thorax, abdomen, and pelvis (2)(3)(4)(5).…”